Searching for Advice After Chimney Fire with Stainless Liner

Hoping for some friendly advice. Thanks in advance.

We live in Maine and had a chimney fire in our newly relined chimney.

We had the original installer/chimney sweep do a cleaning and camera inspection. He discovered a breach in our 1-year-old Lindemann 316L "SmartFlex" stainless steel liner (pics attached). The breach appears to be a couple inches long based on the images. The installer filled the space around the liner with cement containing vermiculite.

The installer and Lindemann both say it's not safe to burn with the breach.

We're now faced with some hard (expensive) decisions.

Question 1: Does this breach really make it unsafe to burn? Breach appears to be about 10 feet from top of chimney.

The installer says he has never removed/replaced a cemented stainless steel liner in his 15 years of business. Lindemann said the liner cannot be repaired and must be replaced.

Question 2: Is removal and re-installation really the only option? As handy people, is there something we could do ourselves?

We have looked at stainless chimney pipe that runs up the outside of the house.

Question 3: Is an external chimney pipe a good and safe option? I've watched videos and read articles and it seems this is a project that we could handle.

Details That Might Help

The chimney is block up to the roof line where it turns into conventional red brick. The red brick was replaced about 10 years ago.

After the new liner was installed, the surface of the chimney was only lukewarm to the touch when burning. There was a noticeable decrease in air flow compared to the terracotta liner that was previously installed. I'm sure this is because of the smaller size of the new liner which has a 7" diameter. The previous terracotta was rectangular with about 40% more volume of space.

After the fire, the installer sent a scope up and found a breach in the new liner about 10 feet below the top of the chimney. This puts the breach at about the location of the attic floor. The firemen said they saw red-hot cinders in about the same location during the fire.

During the chimney fire, the surface of the chimney reached between 140 and 200 degrees in a few places near the location of the breach. During the fire, at the roof line and at the attic floor (near the breach), steam was coming out between blocks. These were the hottest spots during the fire.

 

First answer, yes, the liner needs to be replaced.

Dry wood & regular inspections/cleaning. It is going to be an expensive lesson but you need to burn seasoned wood. Damp wood hastens creosote buildup that leads to flue fires. Regular inspections/cleanings can reduce the risk but properly burning seasoned wood reduces the number of inspections needed. Do you have a stove or an open fireplace?

Properly installed exterior flues are safe & efficient but are also expensive to do it right. Depending on your location it may need to be triple wall insulated or in an insulated chase to get up to a safe operating temperature and not build up creosote again.

Finally, a sweep can replace that liner. He will have to remove the old one & chip out some of the cement/vermiculite. You will have to call around, not all sweeps have the tools to do the job. I would also have a mason/roofer check your chimney to determine where the water is getting in. The steam indicates the bricks were wet. The flashing may need to be redone.

KaptJaq

 

Definitely unsafe to burn with that liner.
As mentioned , and you’ll hear it said over and over, DRY wood and proper burning techniques are key. Without those two things, repairing the chimney is a waist of time and money. You’ll have one chimney fire after the next.
I wonder if a 6” liner can be slid down the existing 7” liner?
Class A insulated stainless chimneys outperform all others IMHO. And they are the cheapest option when starting from scratch. Is your chimney on an outside wall?
What stove are you burning?

 

Agree with above.. Real question is where water getting in? As will steam pressure will break it again?

 

The reason I asked what you are burning in is: If you have a wood stove or insert, check to see what size flue it needs. Most modern stoves only need a 6" liner. If the masonry chimney is sound and you eliminate the water seepage you may get away with just running a 6" liner down the center of the 7". It will be tight but, if there are no sharp bends in the existing flue, it should be doable & legal.

KaptJaq

 

Something doesn't seem quite right about this story.

- You say the liner is only 1 year old? and it broke like that? It's probably warranted for more than a year.
- and you got enough creosote to light off a chim fire in just one year? That was so bad it broke open the liner? Not a garden-variety chimney fire, but a destructive fire. On 1 year usage.
- and the whole thing is cement/vermiculite insulated? Or just the broken part? If the whole thing is lined and cemented, it would be pretty indestructible.

I think these liners, when insulated, are rated over 2000* F. (Tested to 2100f per manufacturer ). Can withstand many chimney fires, per manufacturer. I gotta wonder how that breach got there.

These guys have a good site:
Flexible Chimney Liners Explained - Stainless Steel Flex Flue Liner Info
Their warranty is lifetime. Assuming you are burning wood, not coal.

Bottom line is the photos don't lie; and the liner is damaged and should be replaced; or as suggested relined. (Smart thinking Fox and Kapt). But....I wonder what really happened.

 

Welcome to FHC. We like beer dogs, and lots of pics. And you will find many great people here that are more than willing to help out.

 

water intrusion - could be through mortar joints - seen it time and again on chimneys more so on older assemblies than new. Cause- condensation in flue ( never was a problem much until all the new fangled units with on demand ignition started being installed ) combined with residual byproducts of burnt fuel ( acidic) leaches mortar components. Mortar failure from same more prevalent in northern climates than southern due to temperature swings in the fall and spring. Personal experience on mutiple dwellings .

 

The seam on the liner failed.

By the OP's description,

There was water present. Burning creosote gets very hot very fast. The moisture in the cement/vermiculite quickly expanded into steam. The steam was escaping "between the blocks". My guess is that it also expanded between the liner & the cement fill around the liner. This stretched the liner until the seam failed.

The manufacturer's warranty is under normal conditions. A flue fire with water is not normal conditions.

Get the chimney sealed/pointed/re-flashed then reline the flue.

KaptJaq

 

Unless this is a multi-flue chimney I'd be tempted to remove it all, bricks and blocks and replace it with a standard fabricated chimney.
Maybe leave any masonry that is at the stove not serving as a chimney as a heat sink.

Up through the center of the house is preferred over going up along the outside, mostly for better draft.